This invention relates to a restorative composite dental cement composition, and more particularly, to a dental cement composition having a substantially high compressive strength that is suitable for application with a dental post or as a core build-up material.
Dental restorative cement compositions have achieved wide commercial success and are extensively used in clinical dental practice. The leading U.S. patent on dental restorative cement compositions is U.S. Pat. No. 3,066,112 to Bowen, which describes a dental cement composition that consists of a liquid polymerizable organic resin matrix and finely divided inorganic filler materials.
As described in the Bowen patent, the liquid polymerizable organic resin matrix is typically prepared by combining bisphenol A-glycidyl methacrylate with one or more active monomers, preferably other methacrylates. As part of the system, a catalyst or initiator is used, such as benzoyl peroxide, along with a base or polymerization accelerator such as a toluidine compound. Other ingredients such as stabilizers, absorbents and pigments may be added to the composition.
Although the compositions described in the Bowen patent, as well as those described in subsequent patents and references, are somewhat satisfactory, a major disadvantage of most prior art composite dental cement compositions is that they have a compressive strength when applied which is far from adequate. The compressive strength of a restorative composite dental cement composition is important for enhancing the wearability of the restorative composition.
In U.S. Pat. No. 5,034,433 to Cohen et al., a dental cement is described that is suitable for application with dental posts for post insertion in a tooth or during core formation. The cement includes titanium powder which interacts with the polymer matrix for increasing compressive strength. While the cement is advantageous, it is nevertheless less than desirable since the titanium composite is dark colored.
Accordingly, it would be desirable to provide a restorative composite dental cement composition having a high compressive strength whose viscosity may be varied depending upon the desired dental application.